The present invention relates to an automatic exposure control camera of the aperture priority type.
Recently, in the field of the TTL type camera, there has been developed an automatic exposure control camera of the so-called direct metering type which measures the light of an object coming through a lens into a camera and reflected from a film after the shutter is released thereby to determine a shutter time. The direct metering type camera is advantageous in that since a preset of the shutter time is not required, there is no need of memory elements and therefore the construction of the camera is simple, and that the camera can follow an abrupt change of brightness during the course of shutter release. The camera has the following disadvantages, however. A light receiving range of a photodiode covers an entire viewing screen while a metering characteristic of a metering circuit depends on a center-weighted mean metering in which the metering characteristic is selected placing an emphasis on the central portion of the viewing screen. For photographing an object having extremely light and shade portions, it is preferable to employ a partial metering which meters a limited narrow area in the viewing screen by using a photodiode with a narrow light receiving range. Further, it is advisable that a plurality of portions on the screen, not a single portion, are metered, and a mean value of those metered ones is used to determine a real metering value. For realizing a changeover of the metering range from one to another by the conventional direct metering circuit, a considerably complicated construction is required. Additionally, in the direct metering, it is impossible to calculate the mean value of the partial metered values at the plurality of portions during the shutter operation.